My GNU libstdc++ doesn't include the __cxa_demangle extension because I discovered its implementation to be based on a 5900-line mess of "libiberty" C code making potentially unsafe, not clearly bounded use of alloca. And what do you know: boost was using it wrong.

 -jfw

--- a/boost/python/type_id.hpp
+++ b/boost/python/type_id.hpp
@@ -17,14 +17,6 @@
 # include <boost/type_traits/same_traits.hpp>
 # include <boost/type_traits/broken_compiler_spec.hpp>
 
-#  ifndef BOOST_PYTHON_HAVE_GCC_CP_DEMANGLE
-#   if defined(__GNUC__)                                                \
-    && ((__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 1)))   \
-    && !defined(__EDG_VERSION__)
-#    define BOOST_PYTHON_HAVE_GCC_CP_DEMANGLE
-#   endif
-#  endif
-
 namespace boost { namespace python { 
 
 // for this compiler at least, cross-shared-library type_info
--- a/boost/units/detail/utility.hpp
+++ b/boost/units/detail/utility.hpp
@@ -15,12 +15,8 @@
 #include <typeinfo>
 #include <string>
 
-#if defined(__GLIBCXX__) || defined(__GLIBCPP__)
-#define BOOST_UNITS_USE_DEMANGLING
-#include <cxxabi.h>
-#endif // __GNUC__
-
 #ifdef BOOST_UNITS_USE_DEMANGLING
+#include <cxxabi.h>
 
 #include <boost/algorithm/string/replace.hpp>
 
--- a/libs/graph/test/typestr.hpp
+++ b/libs/graph/test/typestr.hpp
@@ -25,7 +25,8 @@
  */
 template <typename T>
 std::string typestr() {
-#if defined(__GNUC__)
+#if 0
+    /* According to the docs I've found for the clearly non-standard and internal __cxa_demangle, the buffer pointer must be either null or from malloc. -jfw */
     std::size_t const BUFSIZE = 8192;
     std::size_t n = BUFSIZE;
     char buf[BUFSIZE];